1. Technical Field of the Disclosure
The invention relates to a charging and discharging device for the insertion and extraction of a laminating pack in and from a press.
2. Description of the Prior Art
As the press times for the laminating of sheets, particularly with melamine films, amount only to 20 to 30 seconds and the press times for the laminating of paper with urea resin adhesives to 3 to 8 seconds, the handling time required for the charging and discharging of a press represents a significant time and cost factor.
According to the state of the art as seen from German Offenlegungsschrift No. 28 25 206, the laminating pack (which consists of sheets of a wooden material and/or impregnated papers, laminated sheets, veneer or similar hardening layers together with melamine films placed on either side of the sheets of layers) is pressed at l20.degree. C. to 210.degree. C. and pressures of 8 kg/cm.sup.2 to 40 kg/cm.sup.2. The individual layers and the carrier sheet are assembled outside the heat press by means of a collating device and placed on a supporting device, in particular on a roller table, for advancing into the press.
The roller table with the laminating pack subsequently moves from the charging side into the opened heat press. Simultaneously, a movable car which is staggered in height with respect to the roller table travels into the heat press from the discharge side and grips the finished sheet by suction.
Both transfer devices, namely the suction car and the roller table, retract simultaneously from the press area. In the process, the roller table initiates the discharge of the sheet onto a discharge roller band arranged on the top of the suction car. The retracting of the transfer devices and the roller bands is controlled so that the laminating pack is held--supported on its frontal sides--at a distance and in a predetermined position over the press table and so that the laminating pack is placed on the press table at a time which is only immediately prior to pressing and which is approximately simultaneous with the departure of the two transfer devices from the press area. It is difficult during this charging process to coordinate all of the four motion cycles with each other and to regulate them so that the sensitive coating layers of the workpiece will not be damaged.